Journal means for mounting rotary drums

ABSTRACT

Apparatus for journalling the drum or basket of rotating machines and drying machines is provided comprising a bearing having two axially spaced rows of rolling elements arranged between a common inner race ring and an outer race ring. The inner race ring is wider (i.e.: axially longer) than the outer race ring and the rows of bearing elements are axially spaced from each other only a very small distance.

[111 3,822,605 July 9, 1974 United States Patent [191 Schurger et al.

[ JOURNAL MEANS FOR MOUNTING [58] Field of 74/230.3, 230.8, 230.1

ROTARY DRUMS [75] Inventors: Rainer Schurger, Arnsteing; Gunter [56] References Cited UNITED STATES PATENTS Neder; Lothar Walter, both of Schweinfurt; Manfred Brandenstein, Aschfeld; Kurt Feldle, Wurzbur of Germany [73] Assignee: SKF Industrial Trading and 11 3,727,475 4/1973 Steil.....t................ 74/230.8 g, a

Primary Examiner-Leonard H, Gerin Attorney, Agent, or Firm-Murray Schaffer [57] 3 ABSTRACT Apparatus for joumalling the drum or basket of rotat- Development Company B.V., Amsterdam, Netherlands ing machines and drying machines is provided comprising a bearing having two axially spaced rows of 3 7 9 1 9M bl e3 F3 o N L o. mn. FA ll 21 22 ll rolling elements arranged between a common inner race ring and an outer race ring. The inner race rin [30] Foreign Application Priority Data Feb. 17, 1972 Germany..........t....l......

g is wider-(Le; axially longer) than the outer race ring and the rows of bearing elements are axially spaced from each other only a very small distance.

74/230 3 Fl6h 55/34 10 Claims, 9 Drawing Figures PAIENIEUJIIL emu 3.822.605

snwanra PAIENTEDJIJL awn 3.822.605

SHEET 3 BF 4 JOURNAL MEANS FOR MOUNTING ROTARY DRUMS BACKGROUND OF THE INVENTION The present invention relates to an apparatus for rotatably journalling drums or baskets for washing, spinning-, or drying machines and the like.

In general the drum of the above mentioned machines are mounted on a shaft journalled in a roller bearing apparatus comprising at least two rows of roller elements axially spaced one behind the other. The known drum journals of this type require relatively large room in the axial direction since the roller element rows must be spaced some distance from each other. In addition, the construction of such devices is relatively heavy and costly.

It is an object of the present invention to provide journal apparatus for washing machine drums and the like which require very little room in the axial direction without sacrificing any load capacity.

In accordance with the present invention apparatus for journalling the drum or basket of rotating machines and drying machines comprising a bearing having two axially spaced rows of rolling elements arranged between a common inner race ring and an outer race ring. The inner race ring is wider (i.e.: axially longer) than the outer race ring and the rows of bearing elements are axially spaced from each other only a very small distance.

The bearings made in accordance with the present invention can be constructed as unitary assemblies which can be easily installed and removed from the type of machines discussed above. Because of the relative smallness of the outer ring, the room needed for the installation of the bearing in the machine is also very small. Further, even with the small axial distance between the two rows of rolling elements, the load capacity of the bearing is hardly reduced, and particularly not so, when a back-to-back arrangement of double row angular contact bearings is used, since their theoretical bearing distance is relatively large.

Further in accordance with the present invention, each end of the inner ring is provided with a separable flange member to which a drive pulley or the drum are respectively secured. The inner race ring is preferably hollow and is provided with a tie rod which is capable of compressing the flanges against the ends of the inner race ring to hold them securely in place. The flanges and the tie rod or race ring are provided with mating key surfaces, preferably by forming the tie rod or the end of the inner race ring with lands or flats in a square or rectangular cross-section over which the central opening of the flange with a corresponding shape may he slid. This keying system insures that the flanges and inner race rotate conjointly together. Instead of the square cross-section, secure interlocking of the inner race ring and the flanges can be obtained by providing the race ring with axial projections which fit into openings in the flange, or in the carrier disk interposed between the flange and the race ring, to which the flange is secured. Instead of the projections, the race ring, flange or carrier disk can be made with interengaging teeth such as those on a gear or rachet. In any event, because of the compressive force of the tie rod, a unitary and sturdy interlock between the drive end and the driven end (drum) is effected, and the possibility of 2 slippage in the transfer of the rotary moment from the drive means is eliminated. I

A modification of the described. interlocking arrangement can be made by placing double faced gear or teeth disks between the ends of the race ring and the aligned carrier disks, the gear disks are clamped by the tie rod to bite into both the innter race ring and the respective carriers, in the manner of a non-slip clutch.

A particular advantage may be obtained byproviding the outer ring or its surrounding bushing and the bore of the machine housing into which it is placed with a cooperating bayonet type interlocking means. In this manner, the completely assembled bearing unit may be easily installed in the machine.

Another advantage can be obtained by making the outer race ring, in accordance with the present invention, from two pieces of sheet metal and surrounding the same by an annular sleeve, thus forming an annular chamber. The annular chamber may be filled with plastic, rubber or synthetic material which will impart to the sheet metal a rigidity and strength comparable to that obtained by more costly solid forms of races. By chosing the composition, density and amount of plastic, the sheet metal races can be provided with predefined preloading characteristics as well as predefined angular or inclined race surfaces or grooves. Further, the possibility of axial play created by the use of sheet metals alone is avoided and overcome by the use of the plastic filler.

Full details of the present invention follow herein and are shown in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 2 is a view similar to FIG. 1 showing a second embodiment;

FIG. 3 is a similar view showing a third embodiment;

FIG. 3a is a sectional view along lines 3-3 of FIG.

FIG. 4 is a fourth embodiment;

FIG. 4a is a section along line 4-4 of FIG. 4; FIGS. 5 and 6 are yet other embodiments.

DESCRIPTION OF THE INVENTION As seen in the axial section of FIG. 1, the journal apparatus comprises a radial bearing of two rows of rollingelements. The bearing has a tubular inner ring 1 having a pair of axially spaced race grooves on its outer surface, and an outer ring 2 correspondingly grooved between which two rows of balls 3 are located. The inner ring 1 is substantially broader (ie: in the axial direction) than the outer ring 2. Although the axial location of the ball rows with respect to the inner race ring is not critical, it is to be seen in the drawing that the rows be aligned somewhat toward the drive end from the center line transverse to the race ring. That is, the distance from the rows of balls to the drum 7 is greater but only somewhat, than the distance to the drive pulley 9.

An annular securing flanged collar 4 having an angular cross-section is fit over the output side of the outer ring. The collar 4 is made of non-corrosive sheet metal and is provided with a resilient packing ring 5, having a conical cross-section abutting its inwardly radial flange surface. A second angular flanged collar 6 surrounds that output end of the inner ring 1 and is wedged or clamped into secure place by the drum 7 whose mounting flange 8 is bent and held on to the output face of a tie rod shaft 11. The conical packing is vulcanized or otherwise securely adhered to the axial flange surface of the second collar 6 so as to provide an immovable sea].

A drive pulley 9 having a mounting web 10 is secured to the rear face of the tie rod 11. The flange 8 and the web 10 are secured by the rod 11 which is advantageously formed to pass through the inner ring 1.

The tie rod 11 is formed in cross-section as a four sided square shaft whose comer edges are slightly rounded to conform to the inner circumference of the inner ring 1, as seen in FIG. 2. The tie rod 11 is centered within the ring 1, coaxially within it, and is slightly longer than the ring to extend outwardly at both ends. The flange 8 and web 10 have central holes conforming shape to the four sides of the tie rod 11 so that they key thereon. The assembled bearing is axially shoved through the bore of the machine housing 12 and is enclosed by a cover plate 13 which is bolted or otherwise fastened to the housing. The cover has an axial extension or lip which bears against the end of the outer ring 2 forcing the ring to the left, as seen in the drawing, to seat a radial inward shoulder at the output end of the housing 12. fastened to the housing. The cover has an axial extension or lip which bears against the end of the outer ring 2 forcing the ring to the left, as seen in the drawing, to seat a radial inward shoulder at the output end of the housing 12.

The described construction can be modified with respect to the arrangement of locating the square shaft 11 in a centered position within the inner ring 1. Annual end retaining rings may be placed over both ends of the inner ring 1, each of the rings being provided with inwardly directed flanges having a cross-section conforming and corresponding to that of the surface of the tie rod. In this manner the tie rod can be centered within the inner ring I and held against relative rotation with respect to the inner ring I. For example, the angular ring 6 at the output or drive end can be so modified and used.

In FIG. 2 an embodiment is depicted in which a double row angular contact bearing is set in a back-to-back arrangement. Thus, by providing the radial bearings with an inclined bearing component a larger theoretical bearing distance L can be obtained so that the bearing may absorb greater turning moments and loads. The back-to-back arrangement is seen in FIG. 2. The inclined races create thrust vectors which extend angularly to the axis of rotation of the bearing. These vectors cross at the axis of bearing and therefore exert symetrical forces in opposite directions.

The outer ring 2 is formed of two sheet metal sections 14 which are also secured within a sheet metal sleeve 4. The sections 14 are generally conical in cross-section having inclined race grooves annularly thereabout extending angularly with respect to the axis of rotation of the bearing. The sections 14 and the sleeve 4 form an annular chamber which is filled with plastic or other synthetic material 15. The material 15 is poured in liquid form through a hole 16 in the sleeve 4 and sets in place in the annular chamber. Depending on the amount and composition of the material, the axial play of the two rows of roller elements can be avoided. Such play would normally occur because of the inherent tolerance of the sheet metal sections 14 to deformation and resiliency. If particular working or operating conditions are desired, a predefined stress can be placed on the roller elements in the inclined direction by the controlled use of plastic material. To prevent the corrosion of the tie rod 11 a plastic cap 17 may be placed over the head. Otherwise, the embodiment of FIG. 2 is the same as that of FIG. 1.

In FIG. 3 another version of a double row angular contact bearing is shown in which two rows are also set in back-to-back arrangement. In this version, the inner and outer rings 1 and 2 are solid. The inner ring 1 is formed at both of its facial ends with four similar axial projections 18 unifonnly spaced radially about the center as the projections 18 are adapted to fit in corresponding holes 19 formed in an annular carrying disk 20, one of which is slidingly located at each conical end of the inner ring 1. At the input or drive end of the apparatus, the carrying disk 20 is secured to the web 10 of the pulley 9 while at the driven or output end the carrying disk 20 is formed as one unit with the flange 8 to which the drum 7 is secured. Both disks 20 are axially compressed by the tie rod 11 which passes through the inner race ring 1. The tie rod 11 does not have to be force fit within the race ring 1 but may be diametrically significantly smaller. The housing 12 is provided with a radial seal 21 at the output end, which seal is provided on its surface contacting the inner race ring 1 with a sleeve 22 made of highly non-corrosive material. A second seal packing 23 is arranged between the axial end of sleeve 22 and the carrying disk 20.

Because of the direct connection and fastening of both the drive pulley 9 and the drum 7 to the inner race ring 1, the drive moment or torque from the pulley is transferred directly to the drum without any slippage.

In the embodiment shown in FIG. 3 the housing 12 is secured to the machine frame by-a plurality of resilient pads and bolts to provide secure but noise and vibration-free dampening fastening.

In the embodiment of FIG. 4 the bearing arrangement shown in FIG. 3 is modified so that instead of the axial projections 18 and holes 19, a clutch coupling by which the rotary moment is transferred, is fashioned by providing the end faces of the inner race ring 1 and the mating faces of the carrying disk 20 at each of the pulley and drum ends with engaging double sided gear teeth 29. The gear teeth 29 lock into engagement on tightening of the tie rod 11 and act as a unitary non-slip connection. To seal the teeth 29 an annular seal ring 23 is placed surrounding the teeth and clampingly held by the inward compressive action of the carrying disks.

As seen in FIG. 4a, the flange 8 by which the drum is carried is provided with an arcuate projecting lip 30 adapted to seat about the outer periphery of the inner race ring 1. This projection 30 cooperates with the periphery of the inner race ring to permit the drum to be centered properly when the entire assembly is put together.

The advantage of transferring the rotary moment via the interlocking facial teeth 29, which requires only a small space, lies particularly in the fact that when repairs or servicing is necessary, the drum 7 can be easily installed in radial direction without the need to axially slide or move the bearing. The teeth 29 can be made economically and without difficulty by simple forging, die casting or other machining techniques.

In FlG. 5 there is schematically shown a modified form for interlocking the transfer of rotary moment. In this embodiment a gear disk 31 (or corrugated retaining washer or other tooth annular member) is inserted between the abutting faces of the carrying disks 20 and the pulley web on the one side and the drum flange 8 on the other side. The tie rod 11 extends through the disk at the pulley side and is threaded into the disk 20 at the drum side so that upon being tightened the gear disks 31 grasp and hold the elements together in interlocked arrangement against relative rotary moment.

As seen in PK). 6, still another double row angular contact bearing having a back-to-back arrangement is shown. Here the inner race ring 1 is fastened on a pin 24 which carries the drum 7 and which is welded to it. The pulley web 10 is secured to the end of pin 24 by screws 25 and is shaped so that it engages the axial end of inner race ring 1. A radial seal ring 21 is inserted at the drum end of the outer race ring 2 to abut against the surface of a sleeve 22 fixed on the outer surface of the inner race ring 1. Between the sleeve 22 and a shoulder formed on the inner race ring is arranged an elastic ring 26 which permits radial movement of the sleeve 22, so that the seal ring 21 constantly contacts the sleeve 22. The outer race ring 2 is provided with a plurality of axially directed openings on its outer surface at both the input and output ends which are continued by small circumferentially directed grooves about the surface. Radial extending projections 27 formed on the housing 12 enter into these grooves and lock the bearing in the housing in a bayonet type arrangement. To insure against unwanted disassembly screws 28 are inserted axially to hold the outer race ring 2 to the housing 12.

The embodiment of FIG. 6 provides an effortless and low cost construction for a unitary bearing assembly specially for a cantilevered mounting and particularly useful when quick repair or replacement is necessary.

Each of the embodiments described above provides an improved system for the mounting of rotary drums or baskets such as for washing machines or the like. In each the axial and/or radial loads are easily absorbed and taken up by the double row of rolling elements, and even large moments of torque are absorbed readily. The bending action created by the weight in the rotating drum is carried easily by the elongated inner race ring which serves also as the main shaft to transfer of rotary motion. However, the size of the area in the machine in which the bearing is mounted need only be large enough to accomodate the substantially smaller outer race ring.

The construction further permits the building of a unitized bearing assembly which can be easily installed or removed from the machine. The drum, as well as the drive pulleys, can be easily, economically and swiftly attached to it.

Various modifications have been shown. Other modifications and changes will be apparent to those skilled in this art. Accordingly, it is intended that the present disclosure be taken as illustrative only and not limiting of the present invention.

What is claimed is:

1. Apparatus for journalling a rotary drum comprising a bearing having two axially spaced rows of rolling elements arranged between a common inner race ring and an outer race ring, said bearing element rows being spaced apart an axially small distance, flange means carried at each end of said inner race ring to which a drive pulley and a drum are respectively secured, and at least one tie rod extending through said inner race ring securing both said flange means thereto.

2. Apparatus according to claim 1 wherein said flange means and said tie rod are provided withat least one mating land and flat edge whereby they may be keyed together for joint rotation.

3. Apparatus according to claim 1 including carrier means for said flanges interposed between said flanges and the ends of said inner race ring, the ends of said inner race ring having interengaging locking means against relative rotary movement.

4. Apparatus according to claim 3 wherein the ends of said inner race ring have axial projections and said carriers have receiving openings therefore.

5. Apparatus according to claim 3 wherein the ends of said inner race ring and said carriers having mating teeth.

6. Apparatus according to claim 3 wherein said interengaging locking means comprising a toothed disk interposed between the ends of said inner ring and said carriers.

7. Apparatus according to claim 1 wherein at least a portion of the width of said outer ring is covered by a sleeve of thin walled material having a radially inward flange at itsdrum end and is provided with an axial seal packing therebetween.

8. Apparatus according to claim 1 wherein the outer race ring is formed of two pieces of sheet metal and a sleeve forming an annular chamber therebetween, said annular chamber being filled by synthetic material.

9. Apparatus according to claim 1 including radial seal packing means about the surface of the inner ring.

10. Apparatus according to claim 1 wherein the outer race ring is secured within a bore in the machine housing by a detachable bayonet assembly. 

1. Apparatus for journalling a rotary drum comprising a bearing having two axially spaced rows of rolling elements arranged between a common inner race ring and an outer race ring, said bearing element rows being spaced apart an axially small distance, flange means carried at each end of said inner race ring to which a drive pulley and a drum are respectively secured, and at least one tie rod extending through said inner race ring securing both said flange means thereto.
 2. Apparatus according to claim 1 wherein said flange means and said tie rod are provided with at least one mating land and flat edge whereby they may be keyed together for joint rotation.
 3. Apparatus according to claim 1 including carrier means for said flanges interposed between said flanges and the ends of said inner race ring, the ends of said inner race ring having interengaging locking means against relative rotary movement.
 4. Apparatus according to claim 3 wherein the ends of said inner race ring have axial projections and said carriers have receiving openings therefore.
 5. Apparatus according to claim 3 wherein the ends of said inner race ring and said carriers having mating teeth.
 6. Apparatus according to claim 3 wherein said interengaging locking means comprising a toothed disk interposed between the ends of said inner ring and said carriers.
 7. Apparatus according to claim 1 wherein at least a portion of the width of said outer ring is covered by a sleeve of thin walled material having a radially inward flange at its drum end and is provided with an axial seal packing therebetween.
 8. Apparatus according to claim 1 wherein the outer race ring is formed of two pieces of sheet metal and a sleeve forming an annular chamber therebetween, said annular chamber being filled by synthetic material.
 9. Apparatus according to claim 1 including radial seal packing means about the surface of the inner ring.
 10. Apparatus according to claim 1 wherein the outer race ring is secured within a bore in the machine housing by a detachable bayonet assembly. 